Semiconductor device, method for manufacturing the same, and method for mounting the same

ABSTRACT

Disclosed are a semiconductor device, a method for manufacturing the same, and a method for mounting the same. The method for manufacturing a semiconductor device includes the steps of: preparing a package film having a planar configuration whose region is divided into a device-mounting film portion having a device hole forming therein, an external-connection film portion, and a bent portion located between the device-mounting film portion and the external-connection film portion, an external electrode pad being formed on the external-connection film portion on a first surface side of the package film, an inner lead being formed in such a manner as to lead from the device hole to the external electrode pad via the bending portion; mounting a semiconductor chip on the device-mounting film portion on the first surface side by bonding the inner lead to an electrode pad of the semiconductor chip in a region where the device hole is formed; and bending the external-connection film portion at the bending portion 180° toward a second surface side of the package film and fixing the same. The method for mounting a semiconductor device on a mother board in close contact therewith includes the steps of: depositing solder balls on electrode pads of the mother board; and placing the semiconductor device on the mother board and melting the solder balls so as to electrically connect the electrode pads of the mother board and the external electrode pads of the semiconductor device.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a semiconductor device having apackage which has substantially the same size as that of a semiconductorchip and is particularly suitable for a multiple-output semiconductorchip, as well as a method for manufacturing the same and a method formounting the same.

[0003] 2. Description of the Related Art

[0004] Conventionally, packages having substantially the same size assemiconductor chips of this type are called a chip-size package, aμ-BGA, a chip-scale package (CSP), and the like, and various types ofsuch packages have been developed. FIG. 24 is a fragmentary perspectiveview of a semiconductor device having a package of a conventional moldedtype. This semiconductor device is manufactured by forming bumps 242 onelectrode pads of an LSI chip 241, then by resin-encapsulating the LSIchip 241 with a mold resin 243 having substantially the same size asthat of the LSI by using a transfer mold, and finally by depositingsolder balls 244 on external electrodes.

[0005]FIG. 25 shows a cross-sectional view of a semiconductor devicehaving a conventional film (film carrier tape) type. This semiconductordevice is manufactured as follows. The surface of an LSI chip 251 iscoated with an elastic adhesive (elastomer) 252, a polyimide film 255 onwhich inner leads 253 and external connection pads 254 have been formedis secured to the surface of the LSI chip 251 by means of the elasticadhesive 252, the inner leads 253 are bonded to the chip electrode padsof the LSI chip 251, and solder balls 256 are deposited on the externalconnection pads 254.

[0006] In addition, FIG. 26 is a cross-sectional view of a semiconductordevice having a package of a conventional flip chip bonding type. Thissemiconductor device is manufactured by forming bumps 262 on the surfaceof an LSI chip 261, then by effecting face-down bonding the LSI chip 261on a substrate 263 formed of a ceramic or an organic material, and thenby encapsulating the chip by using an encapsulating resin 264. Solderballs 265 are deposited on the reverse surface of the substrate 263. Ifthe package of any one of the types shown in FIGS. 24 to 26 is used, itis possible to manufacture a semiconductor device having a package ofsubstantially the same size as that of the LSI.

[0007] However, with the semiconductor device shown in FIG. 24, anexclusive-use transfer mold is required, which has been a factorhampering the effort in lowering the cost of the semiconductor devices.

[0008] In addition, with the semiconductor device shown in FIG. 25,since a special elastic adhesive is used between the LSI chip and thetape, the contamination of or the damage to the surface of the LSI chipcan occur, possibly deteriorating the reliability. In addition, when theLSI chip and the inner leads are connected, a single bonding method inwhich the leads are bonded one at a time is used. As a result, inmultiple-output packages, the bonding time becomes prolonged, and hasconstituted a factor hampering the effort in lowering the cost of thesemiconductor devices.

[0009] Furthermore, with the semiconductor device shown in FIG. 26, thesubstrate is multilayered in the multiple-output package and isexpensive, and in the case of an LSI chip having a large size, thedifference in the coefficient of thermal expansion between the substrateand the LSI chip in some cases constitutes a problem in the reliability.

SUMMARY OF THE INVENTION

[0010] In view of the above-described circumstances, it is an object ofthe present invention to provide a low-cost, highly reliablesemiconductor device suitable for use in a case where a multiple-outputLSI chip, as well as a method for manufacturing the same and a methodfor mounting the same, thereby overcoming the above-described drawbacksof the conventional art.

[0011] To this end, in accordance with a first aspect of the presentinvention, there is provided a semiconductor device comprising a packagefilm including: a device-mounting film portion on which a semiconductorchip is mounted; an external-connection film portion arranged on thedevice-mounting film portion and having an external electrode pad formedthereon; a bending portion provided between an end portion of thedevice-mounting film portion and an end portion of theexternal-connection film portion; and an inner lead for electricallyconnecting an electrode pad of the semiconductor chip and the externalelectrode pad via the bending portion.

[0012] In accordance with a second aspect of the present invention,there is provided a semiconductor device comprising a package filmincluding: a device-mounting film portion on which a semiconductor chipis mounted such that the device-mounting film portion faces an obversesurface of the semiconductor chip; an external-connection film portionarranged on a reverse surface of the semiconductor chip and having anexternal electrode pad formed thereon; a bending portion providedbetween an end portion of the device-mounting film portion and an endportion of the external-connection film portion; and an inner lead forelectrically connecting an electrode pad of the semiconductor chip andthe external electrode pad via the bending portion.

[0013] In accordance with a third aspect of the present invention, thereis provided a semiconductor device comprising a package film on which asemiconductor chip having an electrode pad arranged in a region along acentral portion of the chip or a center line of the chip is mounted,wherein the package film includes: a device hole formed in a regionalong a central portion thereof or a center line thereof incorrespondence with the region where the electrode pad of thesemiconductor chip is formed; an external electrode pad formed in aregion other than the region where the device hole is formed; and aninner lead connecting the electrode pad of the semiconductor chip andthe external electrode pad.

[0014] In accordance with a fourth aspect of the present invention,there is provided a semiconductor device comprising a package film onwhich a semiconductor chip having an electrode pad arranged in aperipheral portion of the chip is mounted, wherein the package filmincludes: a device hole formed in a peripheral portion thereof incorrespondence with the region where the electrode pad of thesemiconductor chip is formed; an external electrode pad formed in aregion other than the region where the device hole is formed; and aninner lead connecting the electrode pad of the semiconductor chip andthe external electrode pad, wherein a space between the package film anda surface of the semiconductor chip is fixed by an encapsulating resin.

[0015] In accordance with a fifth aspect of the present invention, thereis provided a semiconductor device comprising a package film including:a device-mounting film portion on which a semiconductor chip having anelectrode pad arranged in a predetermined region is mounted such thatthe device-mounting film portion faces an obverse surface of thesemiconductor chip; an external-connection film portion arranged on areverse surface of the semiconductor chip and having an externalelectrode pad formed thereon; a bending portion provided between an endportion of the device-mounting film portion and an end portion of theexternal-connection film portion; and an inner lead, wherein thedevice-mounting film portion has a device hole formed in a predeterminedregion in correspondence with a region where an electrode pad of thesemiconductor chip is formed and an external electrode pad formed in aregion other than the region where the device hole is formed, and theinner lead electrically connects the electrode pad of the semiconductorchip and the external electrode pad of the device-mounting film portion,and electrically connects the electrode pad of the semiconductor chipand the external-connection film portion via the bending portion.

[0016] In accordance with a sixth aspect of the present invention, thereis provided a method for manufacturing a semiconductor device,comprising the steps of: preparing a package film having a planarconfiguration whose region is divided into a device-mounting filmportion having a device hole forming therein, an external-connectionfilm portion, and a bent portion located between the device-mountingfilm portion and the external-connection film portion, an externalelectrode pad being formed on the external-connection film portion on afirst surface side of the package film, an inner lead being formed insuch a manner as to lead from the device hole to the external electrodepad via the bending portion; mounting a semiconductor chip on thedevice-mounting film portion on the first surface side by bonding theinner lead to an electrode pad of the semiconductor chip in a regionwhere the device hole is formed; and bending the external-connectionfilm portion at the bending portion 180° toward a second surface side ofthe package film and fixing the same.

[0017] In accordance with a seventh aspect of the present invention,there is provided a method for manufacturing a semiconductor device,comprising the steps of: preparing a package film having a planarconfiguration whose region is divided into a device-mounting filmportion having a device hole forming therein, an external-connectionfilm portion, and a bent portion located between the device-mountingfilm portion and the external-connection film portion, an externalelectrode pad being formed on the external-connection film portion on afirst surface side of the package film, an inner lead being formed insuch a manner as to lead from the device hole to the external electrodepad via the bending portion; mounting a semiconductor chip on thedevice-mounting film portion on a second surface side of the packagefilm by bonding the inner lead to an electrode pad on an obverse surfaceof the semiconductor chip in a region where the device hole is formed;and bending the external-connection film portion at the bending portion180° toward a reverse surface side of the semiconductor chip and fixingthe same to the reverse surface.

[0018] In accordance with an eighth aspect of the present invention,there is provided a method for manufacturing a semiconductor device,comprising the steps of: preparing a semiconductor chip having anelectrode pad arranged in a region along a central portion of the chipor a center line of the chip, as well as a package film having a devicehole formed in a region along a central portion thereof or a center linethereof in correspondence with the region where the electrode pad of thesemiconductor chip is formed, an external electrode pad being formed onan external connection surface side of the package film in a regionother than the region where the device hole is formed, an inner leadbeing formed in such a manner as to lead from the device hole to theexternal electrode; and mounting the semiconductor chip on a devicemounting surface side of the package film by bonding the inner lead tothe electrode pad of the semiconductor chip in the region where thedevice hole is formed.

[0019] In accordance with a ninth aspect of the present invention, thereis provided a method for manufacturing a semiconductor device,comprising the steps of: preparing a semiconductor chip having anelectrode pad arranged in a peripheral portion of the chip, as well as apackage film having a device hole formed in a peripheral portion thereofin correspondence with the region where the electrode pad of thesemiconductor chip is formed, an external electrode pad being formed onan external connection surface side of the package film in a regionother than the region where the device hole is formed, an inner leadbeing formed in such a manner as to lead from the device hole to theexternal electrode; and mounting the semiconductor chip on a devicemounting surface side of the package film by bonding the inner lead tothe electrode pad of the semiconductor chip in the region where thedevice hole is formed, and by allowing an encapsulating resin to flowinto a space between the package film and an obverse surface of thesemiconductor chip.

[0020] In accordance with a 10th aspect of the present invention, thereis provided a method for manufacturing a semiconductor device,comprising the steps of: preparing a semiconductor chip having electrodepads arranged in a predetermined region thereof, as well as a packagefilm having a planar configuration whose region is divided into adevice-mounting film portion having a device hole forming in adetermined region thereof, an external-connection film portion, and abent portion located between the device-mounting film portion and theexternal-connection film portion, external electrode pads being formedon the external-connection film portion on a first surface side of thepackage film and in a region other than the region where the device holeis formed in the device-mounting film portion on the first surface side,inner leads being formed in such a manner as to lead from the devicehole to respective the external electrode pads; mounting thesemiconductor chip on the device-mounting film portion on a secondsurface side of the package film by bonding the inner leads to theelectrode pads on an obverse surface of the semiconductor chip in aregion where the device hole is formed; and bending theexternal-connection film portion at the bending portion 180° toward areverse surface side of the semiconductor chip and fixing the same tothe reverse surface.

[0021] In accordance with an 11th aspect of the present invention, thereis provided a method for mounting a semiconductor device on a motherboard in close contact therewith, comprising the steps of: depositingsolder balls on electrode pads of the mother board; and placing thesemiconductor device on the mother board and melting the solder balls soas to electrically connect the electrode pads of the mother board andthe external electrode pads of the semiconductor device

[0022] In accordance with a 12th aspect of the present invention, thereis provided a method for mounting a semiconductor device in which aplurality of superposed semiconductor devices are mounted on a motherboard, comprising the step of: causing the external electrode padsformed on one of the external-connection film portion and thedevice-mounting film portion of a first semiconductor device to besuperposed on the electrode pads of the mother board, and causing theexternal electrode pads formed on one of the external-connection filmportion and the device-mounting film portion of a second semiconductordevice to be superposed on the external electrode pads formed on anotherfilm portion of the first semiconductor device, so as to electricallyconnect the superposed electrodes.

[0023] The above and other objects, features and advantages of thepresent invention will become more apparent from the following detaileddescription of the invention when read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024]FIG. 1A is a top view, taken from an inner-lead forming surface(first surface) side, of a package film used in a semiconductor devicein accordance with a first embodiment of the present invention;

[0025]FIG. 1B is a cross-sectional view taken along line A-A′ in FIG.1A;

[0026]FIG. 1C is a cross-sectional structural diagram in the course ofmanufacture of the semiconductor device in accordance with the firstembodiment of the present invention;

[0027]FIG. 1D is a cross-sectional structural diagram in the course ofmanufacture of the semiconductor device in accordance with the firstembodiment of the present invention;

[0028]FIG. 1E is a cross-sectional structural diagram of thesemiconductor device in accordance with the first embodiment of thepresent invention;

[0029]FIG. 2A is a cross-sectional view of a package film used in asemiconductor device in accordance with a second embodiment of thepresent invention;

[0030]FIG. 2B is a cross-sectional structural diagram of thesemiconductor device in accordance with the second embodiment of thepresent invention;

[0031]FIG. 3A is an overall cross-sectional view of a semiconductordevice in accordance with a third embodiment of the present invention;

[0032]FIG. 3B is an enlarged partial cross-sectional view of a region Eshown in FIG. 3A;

[0033]FIG. 4A is a cross-sectional structural diagram of a semiconductordevice in accordance with a fourth embodiment of the present inventionin which the semiconductor device in the first embodiment of the presentinvention is provided with a box-shaped protective frame;

[0034]FIG. 4B is a cross-sectional structural diagram of thesemiconductor device in accordance with the fourth embodiment of thepresent invention in which the semiconductor device in the firstembodiment of the present invention is provided with a bottomlessprotective frame;

[0035]FIG. 5 is a cross-sectional structural diagram of a semiconductordevice in accordance with a fifth embodiment of the present invention;

[0036]FIG. 6 is a cross-sectional structural diagram of a semiconductordevice in accordance with a sixth embodiment of the present invention;

[0037]FIG. 7A is a cross-sectional structural diagram of a semiconductordevice in accordance with a seventh embodiment of the present invention;

[0038]FIG. 7B is a diagram illustrating the process of manufacturing thesemiconductor device in accordance with the seventh embodiment of thepresent invention;

[0039]FIG. 8A is a cross-sectional structural diagram of a semiconductordevice in accordance with an eighth embodiment of the present invention;

[0040]FIG. 8B is a diagram illustrating the process of manufacturing thesemiconductor device in accordance with the eighth embodiment of thepresent invention;

[0041]FIG. 9A is a front elevational view, taken from the inner-leadforming surface (first surface) side, of a package film used in asemiconductor device in accordance with a ninth embodiment of thepresent invention;

[0042]FIG. 9B is a cross-sectional view taken along line A-A′ in FIG.9A;

[0043]FIG. 10 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 10th embodiment of the present invention;

[0044]FIG. 11 is a cross-sectional structural diagram of a semiconductordevice in accordance with an 11th embodiment of the present invention;

[0045]FIG. 12A is a cross-sectional structural diagram of asemiconductor device in accordance with a 12th embodiment of the presentinvention in which the semiconductor device in the ninth embodiment ofthe present invention is provided with the box-shaped protective frame;

[0046]FIG. 12B is a cross-sectional structural diagram of thesemiconductor device in accordance with the 12th embodiment of thepresent invention in which the semiconductor device in the ninthembodiment of the present invention is provided with the bottomlessprotective frame;

[0047]FIG. 13 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 13th embodiment of the present invention;

[0048]FIG. 14 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 14th embodiment of the present invention;

[0049]FIG. 15A is a top view, taken from the inner-lead forming surface(first surface) side, of a package film used in a semiconductor devicein accordance with a 15th embodiment of the present invention;

[0050]FIG. 15B is a cross-sectional view taken along line A-A′ in FIG.15A;

[0051]FIG. 16A is a cross-sectional structural diagram of asemiconductor device in accordance with a 16th embodiment of the presentinvention in which the semiconductor device in the 15th embodiment ofthe present invention is provided with the box-shaped protective frame;

[0052]FIG. 16B is a cross-sectional structural diagram of thesemiconductor device in accordance with the 16th embodiment of thepresent invention in which the semiconductor device in the 15thembodiment of the present invention is provided with the bottomlessprotective frame;

[0053]FIG. 17 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 17th embodiment of the present invention;

[0054]FIG. 18A is a top view, taken from an external connection surfaceside, of a package film used in a semiconductor device in accordancewith an 18th embodiment of the present invention;

[0055]FIG. 18B is a cross-sectional view taken along line A-A′ in FIG.18A;

[0056]FIG. 18C is a cross-sectional structural diagram of thesemiconductor device in accordance with the 18th embodiment of thepresent invention;

[0057]FIG. 19A is a top view, taken from the external connection surfaceside, of a package film used in a semiconductor device in accordancewith a 19th embodiment of the present invention;

[0058]FIG. 19B is a cross-sectional view taken along line A-A′ in FIG.19A;

[0059]FIG. 20 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 20th embodiment of the present invention;

[0060]FIG. 21A is a cross-sectional structural diagram of asemiconductor device in accordance with a 21st embodiment of the presentinvention in which the semiconductor device in the 19th embodiment ofthe present invention is provided with the box-shaped protective frame;

[0061]FIG. 21B is a cross-sectional structural diagram of thesemiconductor device in accordance with the 21st embodiment of thepresent invention in which the semiconductor device in the 19thembodiment of the present invention is provided with the bottomlessprotective frame;

[0062]FIG. 22 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 22nd embodiment of the present invention;

[0063]FIG. 23 is a cross-sectional structural diagram of a semiconductordevice in accordance with a 23rd embodiment of the present invention;

[0064]FIG. 24 is a fragmentary perspective view of a semiconductordevice having a package of the conventional molded type;

[0065]FIG. 25 is a cross-sectional structural diagram of a semiconductordevice having a package of the conventional film type;

[0066]FIG. 26 is a cross-sectional structural diagram of a semiconductordevice having a package of the conventional flip chip bonding type;

[0067]FIG. 27A is a schematic cross-sectional view of an essentialportion of a mother board used in the mounting of a semiconductor devicein accordance with the present invention on a mother board;

[0068]FIG. 27B is a cross-sectional structural diagram illustrating themounting of a semiconductor device in accordance with the presentinvention on a mother board; and

[0069]FIG. 28 is a cross-sectional structural diagram in which aplurality of semiconductor devices in accordance with the presentinvention are laminated and mounted on a mother board.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0070]FIGS. 1A to 1E are diagrams illustrating the structure of asemiconductor device and a process for manufacturing the same inaccordance with a first embodiment of the present invention. FIG. 1A isa top view, taken from an inner-lead forming surface (first surface) 1Aside, of a package film 1 used in this semiconductor device. FIG. 1B isa cross-sectional view taken along line A-A′ in FIG. 1A. FIGS. 1C and 1Dare cross-sectional structural diagrams in the course of manufacture ofthe semiconductor device in accordance with the first embodiment. FIG.1E is a cross-sectional structural diagram of the semiconductor devicein accordance with the first embodiment.

[0071] First, the package film 1 is fabricated, as shown in FIGS. 1A and1B. That is, inner leads 3 are formed on a polyimide base resin 2 inwhich a device hole 12 has been formed in a predetermined area for adevice-mounting film portion by press punching and in which a bendinghole 13 has been formed in a predetermined area for a bent portion.Here, the inner leads 3 are formed, for instance, by attaching a copperfoil to the surface of the base resin 2, subjecting the copper foil topatterning by photolithographic etching, and then soldering ortin-plating the etched copper foil. Reference numeral 3 a in thedrawings denote dummy inner leads. Next, an insulating resin 4 is coatedon the base thus prepared, electrode pad holes 4 a are formed in theinsulating resin 4 by photolithographic etching to allow the inner leads3 to be exposed, thereby forming external electrode pads 5.Incidentally, the external electrode pads 5 may be formed b selectingcoating (patterning) the insulating resin 4 by a printing method. Inaddition, it is preferable to coat a polyimide-based elastic resin 6 onone surface or both surfaces of the inner leads 3 in a bending portion 1d for the purpose of preventing the deterioration of the strength of theinner leads 3 or disconnection thereof. Thus the package film 1 isfabricated. It should be noted that in a case where the tape automatedbonding (TAB) manufacturing technology, a plurality of package films 1are fabricated and supplied onto a film carrier tape 1 a.

[0072] Next, as shown in FIG. 1C, the inner-lead forming surface 1A(first surface) of the package film 1 is made to oppose the surface ofan LSI chip 8, and the LSI chip 8 is mounted on a device-mounting filmportion 1 b of the package film 1. That is, in the device-mounting filmportion 1 b of the package film 1, the inner leads 3 and the dummy innerleads 3 a are collectively bonded by thermo-compression bonding to chipelectrode pads 8 a of the LSI chip 8 on which gold-plated bumps 7 havebeen formed. Then, an encapsulating resin 9, such as an epoxy resin, isallowed to flow into a space formed by the device-mounting film portion1 b and the surface of the LSI chip 8, thereby fixing and mounting theLSI chip 8 with respect to the device-mounting film portion 1 b. Here,the dummy inner leads 3 a have the function of preventing the innerleads 3 from becoming disconnected or the bonded portions from becomingpeeled off from the time the inner leads 3 are bonded until the LSI chip8 is fixed. Incidentally, in the case where the TAB technology is used,the package films 1 are separated from the film carrier tape 1 a bypunching after completion of the mounting of the LSI chip 8. Since theinner leads are collectively bonded to the electrode pads of thesemiconductor chip in the above-described manner, the number ofprocessing steps can be reduced, and the manufacturing cost can belowered, so that it possible to lower the cost of the packages.

[0073] Next, as shown in FIG. 1D, an external-connection film portion 1c of the package film 1 is bent 180° at the bending portion 1 d toward abase-resin surface 1B (second surface), and is secured to the surface ofthe encapsulating film 9 in the device-mounting film portion 1 b bymeans of an adhesive 10. Here, a point of bending is set, for example,to a position about 1 mm spaced apart from an outer side surface of theLSI chip 8. Finally, as shown in FIG. 1E, solder balls 11 are depositedon the external electrode pads 5.

[0074] Thus, in accordance with the first embodiment, the inner leads 3(and the dummy inner leads 3 a) formed in such a manner as to projectinto the device hole 12 of the device-mounting film portion 1 b arecollectively bonded to the chip electrode pads 8 a of the LSI chip 8 tomount the LSI chip 8 on the device-mounting film portion 1 b, theexternal-connection film portion 1 c is bent 180° at the bending portion1 d (abut 1 mm spaced apart from the outer side of the LSI chip 8) andis secured to the device-mounting film portion 1 b. As a result, since aspecial elastic adhesive is not used, it is possible to improve thereliability. In addition, since the inner leads are collectively bondedto the LSI chip without using an exclusive-use transfer mold, it ispossible to lower the manufacturing cost, so that it is possible tolower the cost of the packages.

[0075] It should be noted that a structure may be adopted in which, asshown in FIG. 1D, the solder balls 11 are not deposited on the externalelectrode pads 5 without executing the step shown in FIG. 1E. When thischip-size package is mounted on a mother board, satisfactory connectionsare made possible by supplying solder balls to the mother board side. Aprinting technique, for example, is used in supplying the solder ballsto the mother board. As the solder balls are thus supplied to the motherboard side, it becomes possible to mount a plurality of packagessimultaneously. Hence, it is possible to reduce the number of steps inthe mounting of packages onto the mother board. In addition, in theprocess for manufacturing the packages, the step for depositing thesolder balls on the external electrode pads is not required, and thenumber of processing steps can be reduced, thereby making it possible tofurther lower the cost of the semiconductor device.

[0076]FIGS. 2A and 2B are diagrams illustrating the structure of asemiconductor device and a process for manufacturing the same inaccordance with a second embodiment of the present invention. FIG. 2A isa cross-sectional view of a package film 21 used in this semiconductordevice, and FIG. 2B is a cross-sectional structural diagram of thesemiconductor device in accordance with the second embodiment.

[0077] First, the package film 21 is formed, as shown in FIG. 2A. Thatis, the base resin 2 is subjected to press punching, thereby forming thedevice hole 12, the bending hole 13, and electrode pad holes 2 a forforming external electrode pads 22. Then, in the same procedure as thatof the first embodiment, the inner leads 3 and the dummy inner leads 3 aare formed on this base resin 2, and the insulating resin 4 is coatedthereon. In addition, it is preferable to coat a bending portion 21 dwith the elastic resin 6. Thus the package film 21 having the externalelectrode pads 22 with openings facing a base-resin surface 21B (firstsurface) is fabricated.

[0078] Next, as shown in FIG. 2B, the LSI chip 8 is mounted on adevice-mounting film portion 21 b of the package film 21 with thebase-resin surface 21B set on the LSI chip 8 side. Namely, in the sameprocedure as that of the above-described first embodiment, the innerleads 3 and the dummy inner leads 3 a are bonded to the chip electrodepads 8 a of the LSI chip 8 where the bumps 7 have been formed. Then, theLSI chip 8 is fixed and mounted on the device-mounting film portion 21 bby the encapsulating resin 9, and an external-connection film portion 21c is bent 180° at the bending portion 21 d toward an inner-lead formingsurface 21A (second surface), and is secured to the surface of theencapsulating film 9 in the device-mounting film portion 21 b by meansof the adhesive 10. Finally, the solder balls 11 are deposited on theexternal electrode pads 22.

[0079] As described above, in accordance with the second embodiment, inthe process for fabrication of the package film, the electrode pad holes2 a are formed in advance during the press punching of the device hole12 and the like, and the external electrode pads 22 are formed in theelectrode pad holes 2 a by subjecting the inner leads 3 to patterning.As a result, it is possible to reduce the number of fabrication steps ofthe package film (the number of processing steps of thephotolithographic etching of the insulating resin) and reduce thematerial cost (insulating resin), thereby making it possible to furtherlower the cost of the semiconductor device.

[0080] Incidentally, in FIG. 2B, a structure may be adopted in which thesolder balls 11 are not deposited on the external electrode pads 22.

[0081] A third embodiment of the present invention is characterized inthat the inner leads are bonded directly to the electrode pads of theLSI chip without forming the bumps. FIGS. 3A and 3B are cross-sectionalstructural diagrams of a semiconductor device in accordance with thethird embodiment of the present invention, in which FIG. 3A is anoverall cross-sectional view, and FIG. 3B is a partial cross-sectionalview of a region E shown in FIG. 3A. It should be noted that thestructure and the manufacturing process other than those described beloware the same as those of the above-described first embodiment.

[0082] In FIGS. 3A and 3B, inner leads 31 are formed by subjecting acopper foil 31 a to gold plating 31 b and by annealing the same at 150°C. for 30 minutes or thereabouts (the same holds true of the dummy innerleads). The inner leads 31 and the dummy inner leads are collectivelybonded directly to the chip electrode pads 8 a of the LSI chip 8 bythermo-compression bonding without the bumps.

[0083] Generally, if the bumps are not provided, the damage to theelectrode pads of the LSI chip is large, and cracks or the like occurbelow the pads. However, as for the inner leads 31 formed by subjectingthe copper foil 31 a to the gold plating 31 b, their hardness can belowered by annealing or the like. Hence, by using the softened innerleads 31, direction bonding is made possible in which the damage to thechip electrode pads is alleviated and cracks or the like do not occurbelow the pads.

[0084] Thus, in accordance with the third embodiment, since the processfor forming the bumps on the electrode pads of the LSI chip is madeunnecessary, it is possible to reduce the manufacturing cost, therebymaking it possible to lower the cost of the semiconductor device.

[0085] Incidentally, it goes without saying that this third embodimentis also applicable to the above-described second embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0086] A fourth embodiment of the present invention is characterized inthat a protective frame is provided for protecting the side surfaces andthe reverse surface of the LSI chip. FIGS. 4A and 4B are cross-sectionalstructural diagrams illustrating a semiconductor device in accordancewith the fourth embodiment of the present invention. This semiconductordevice is arranged such that the semiconductor device in accordance withthe above-described first embodiment is provided with a box-shapedprotective frame 41 as shown in FIG. 4A or a bottomless protective frame42 as shown in FIG. 4B. The protective frame 41 is provided in such amanner as to cover the side surfaces and the reverse surface of the LSIchip 8, while the protective frame 42 is provided in such a manner as tocover the side surfaces of the LSI chip 8. These protective frames 41and 42 are obtained by forming an insulating material or an electricallyconductive material, such as a resin or a metal, and are fixed to thedevice-mounting film portion 1 b of the package film 1 by means of anadhesive 10 b.

[0087] Thus, in accordance with the fourth embodiment, since theprotective frame 41 or 42 is provided, the side surfaces and the reversesurface of the LSI chip 8 can be protected, with the result that it ispossible to prevent the occurrence of the breakage of the side surfacesand the reverse surface of the LSI chip 8 during its handling, and animprovement in the yield during mounting can be expected.

[0088] Incidentally, it goes without saying that this fourth embodimentis also applicable to the above-described second or third embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0089] A fifth embodiment of the present invention is characterized inthat a flat plate is provided for improving the flatness of theexternal-connection film portion. FIG. 5 is a cross-sectional structuraldiagram of a semiconductor device in accordance with the fifthembodiment of the present invention. The semiconductor device shown inFIG. 5 is arranged such that, in the semiconductor device in accordancewith the above-described first embodiment, a flat plate 51 formed of aninsulating material or an electrically conductive material such as ametal is provided between the device-mounting film portion 1 b and theexternal-connection film portion 1 c of the package film 1. This flatplate 51 is fixed between the surface of the encapsulating resin 9 ofthe device-mounting film portion 1 b and the external-connection filmportion 1 c by using adhesives 10 a and 10 b. As the procedure forattaching the flat plate 51, after the completion of the step shown inFIG. 1B, for example, the flat plate 51 is fixed to anencapsulating-resin forming portion of the device-mounting film portion1 b by means of the adhesive 10 a, and the external-connection filmportion 1 c is then bent 180° and is fixed to the flat plate 51 by meansof the adhesive 10 b.

[0090] Thus, in accordance with the fifth embodiment, since the flatplate 51 is provided between the device-mounting film portion 1 b andthe external-connection film portion 1 c, the flatness of theexternal-connection film portion 1 c and the solder balls 11 can beimproved. Hence, it is possible to improve the mountability of thesemiconductor device onto a mother board. In addition, in the case wherea metal plate or the like is used as the flat plate, it is possible toimprove the heat radiation characteristic of the semiconductor device.

[0091] Incidentally, it goes without saying that this fifth embodimentis also applicable to the above-described second, third, or fourthembodiment. In addition, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

[0092] A sixth embodiment of the present invention is characterized inthat a substantially U-shaped plate is provided for improving theflatness of the external-connection film portion and for protecting thereverse surface of the LSI chip. FIG. 6 is a cross-sectional structuraldiagram of a semiconductor device in accordance with the sixthembodiment of the present invention. The semiconductor device shown inFIG. 6 is arranged such that a substantially U-shaped plate 61 formedsubstantially into a U shape by using an insulating material or anelectrically conductive material such as a metal is provided in thesemiconductor device in accordance with the above-described firstembodiment. The LSI chip 8 is attached to the inner surface of a bottomplate portion 61 a of the substantially U-shaped plate 61 (hence, thedevice-mounting film portion 1 b and the LSI chip 8 are located betweenthe bottom plate 61 a and a top plate portion 61 b), and theexternal-connection film portion 1 c is attached to the outer surface ofthe top plate portion 61 b. As the procedure for attaching thesubstantially U-shaped plate 61, after the completion of the step shownin FIG. 1B, for example, the bottom surface of the LSI chip 8 is fixedto the bottom plate portion 61 a by means of the adhesive 10 a, and theexternal-connection film portion 1 c is then bent 180° and is fixed tothe top plate portion 61 b by means of the adhesive 10 b. Alternatively,in the case where the metal plate or the like is used as thesubstantially U-shaped plate 61, the LSI chip 8 is fixed to the flatplate, the remaining portion of the flat plate is turned back 180° toform the substantially U-shaped plate 61, and the external-connectionfilm portion 1 c is finally bent 180° and is fixed to the top plateportion 61 b. Incidentally, although, in FIG. 6, the orientation of theinner surface of the bending portion 1 d of the package film 1 (fromright to left) and the orientation of the inner surface of a curvedportion 61 c of the substantially U-shaped plate (from left to right)are in a positional relationship of being offset from each other 180° ina plan view, but may be set in a positional relationship of being offsetfrom each other 90° in a plan view.

[0093] Thus, in accordance with the sixth embodiment, since thearrangement provided is such that, by using the substantially U-shapedplate 61, the LSI chip 8 is attached to the inner surface of the bottomplate portion 61 a thereof, and the external-connection film portion 1 cis attached to the outer surface of the top plate portion 61 b, it ispossible to improve the flatness of the external-connection film portion1 c and the solder balls 11, and protect the LSI chip. In addition, inthe case where a metal plate or the like is used as the substantiallyU-shaped plate 61, it is possible to further improve the heat radiationcharacteristic of the package.

[0094] Incidentally, it goes without saying that this sixth embodimentis also applicable to the above-described second or third embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0095] A seventh embodiment of the present invention is characterized inthat the external-connection film portion is formed as a two-layeredstructure in which both surfaces are electrically conductive. FIGS. 7Aand 7B are diagrams illustrating the structure of a semiconductor deviceand a manufacturing process in accordance with the seventh embodiment ofthe present invention.

[0096] First, as shown in FIG. 7A, a package film 71 having a throughhole 2 b for a reference power supply (grounded power supply) is formedin an external-connection film portion 71 c. Namely, when the devicehole and the bending hole are formed in the base resin 2, the throughhole 2 b is also formed simultaneously by press punching, and areference (grounded) power supply inner lead 3 b is formed in such amanner as to lead to the through hole 2 b. Subsequently, the packagefilm 71 is fabricated in the same procedure as that of theabove-described first embodiment. Next, in the same procedure as that ofthe above-described first embodiment, the LSI chip 8 is mounted on thepackage film 71. Then, in the same procedure as that of theabove-described fifth embodiment, the external-connection film portion71 c is bent, an electrically conductive flat plate 72 is providedbetween a device-mounting film portion 71 b and the external-connectionfilm portion 71 c by means of the adhesives 10 a and 10 b, and theadhesive 10 b at the bottom of the through hole 2 b is removed.

[0097] Next, as shown in FIG. 7B, a solder ball 11 a (electricallyconductive material) is deposited in the through hole 2 b (at this time,the solder balls 11 are deposited on the external electrode pads 5).Next, this chip-size package is subjected to heat treatment to melt thesolder ball 11 a, so as to allow the reference power supply inner lead 3b and the flat plate 72 (serving as the reference power supply) to beelectrically connected to each other. Incidentally, the volume of thethrough hole 2 b and the volume of the solder ball 11 a shouldpreferably be substantially identical.

[0098] Thus, in accordance with the seventh embodiment, since, on theone hand, the electrically conductive flat plate 72 provided between thedevice-mounting film portion 71 b and the external-connection filmportion 71 c and, on the other hand, the reference power supply innerlead 3 b are electrically connected so as to provide the two-layeredstructure in which both surfaces are electrically conductive, it ispossible to improve the flatness of the external-connection filmportion, improve the heat radiation characteristic of the LSI chip, andreduce the crosstalk noise. Therefore, the operating speed of the LSIchip can be made faster.

[0099] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. Further, the inner leads may be bonded directly tothe chip electrode pads without using bumps as in the above-describedthird embodiment. In addition, an electrically conductive substantiallyU-shaped plate such as the one use in the above-described sixthembodiment may be used without using the electrically conductive flatplate. Still further, it is possible to adopt the structure in which thesolder balls 11 are not deposited on the external electrode pads 5.

[0100] An eighth embodiment of the present invention is characterized inthat the external-connection film portion is bent toward the reversesurface of the LSI chip and is fixed thereto. FIGS. 8A and 8B arediagrams illustrating the structure of a semiconductor device and amanufacturing process in accordance with the eighth embodiment of thepresent invention. Incidentally, in FIGS. 8A and 8B, those parts andportions which are identical to those shown in FIGS. 1 to 7 are denotedby the same reference numerals.

[0101] First, as shown in FIG. 8A, by using the package film 1 in theabove-described first embodiment (see FIGS. 1A and 1B), the LSI chip 8is mounted on the base resin surface 1B of the device-mounting filmportion 1 b in a state in which the base-resin surface 1B (secondsurface) of the package film 1 is set as the LSI chip 8 side. Namely, inthe device-mounting film portion 1 b of the package film 1, the innerleads 3 and the dummy inner leads 3 a are collectively bonded bythermo-compression bonding to the chip electrode pads 8 a of the LSIchip 8 on which the bumps 7 have been formed. Then, the encapsulatingresin 9 is allowed to flow into the space formed by the device-mountingfilm portion 1 b and the surface of the LSI chip 8, thereby fixing andmounting the LSI chip 8 with respect to the device-mounting film portion1 b.

[0102] Then, as shown in FIG. 8B, the external-connection film portion 1c is bent 180° at the bending portion 1 d in such a manner as to besuperposed on a reverse surface 8 b side of the LSI chip 8, and issecured to the reverse surface 8 b of the chip by means of the adhesive10. Finally, the solder balls 11 are deposited on the external electrodepads 5.

[0103] Thus, in accordance with the eighth embodiment, since theexternal-connection film portion 1 c is bent toward the reverse surface8 b of the LSI chip 8 and is secured thereto, it is possible to protectthe reverse surface 8 b and the side surfaces of the LSI chip 8 withoutusing a protective frame or the like. In addition, it is possible toflatten the external-connection film portion 1 c without using a flatplate. Furthermore, it is possible to lower the cost of thesemiconductor device and improve its reliability.

[0104] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdembodiment. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

[0105] A ninth embodiment of the present invention is characterized inthat the package film having external-connection film portions on bothsides of the device-mounting film portion is used, and theseexternal-connection film portions are respectively bent. FIGS. 9A and 9Bare diagrams illustrating the structure of a semiconductor device and amanufacturing process in accordance with the ninth embodiment of thepresent invention. FIG. 9A is a front elevational view in which apackage film 91 used in this semiconductor device is viewed from theinner-lead forming surface. FIG. 9B is a cross-sectional structuralview, taken along line A-A′ of FIG. 9A, of the semiconductor device inaccordance with the ninth embodiment. Incidentally, in FIGS. 9A and 9B,those parts and portions which are identical to those shown in FIGS. 1to 8 are denoted by the same reference numerals.

[0106] First, the package film 91 shown in FIG. 9A is fabricated by thesame procedure as that of the above-described first embodiment. Namely,the inner leads 3 are formed by effecting patterning on the base resin 2in which the device hole 12 and two bending holes 13 a and 13 b havebeen formed. Then, the insulating resin 4 is formed by effectingpatterning thereon, thereby forming the external electrode pads 5. Itshould be noted that dummy inner leads are unnecessary. In addition, theelastic resin 6 should preferably be coated to prevent the deteriorationof the strength of the inner leads 3 in bending portions 91 d and 91 f(portions where the bending holes 13 a and 13 b are formed). The packagefilm 1 is fabricated in the above-described manner.

[0107] Next, as shown in FIG. 9B, the LSI chip 8 is mounted on adevice-mounting film portion 91 b in a state in which an inner-leadforming surface 91A (first surface) of a device-mounting film portion 91b of the package film 91 faces the surface of the LSI chip 8. Namely, inthe device-mounting film portion 91 b of the package film 91, the innerleads 3 are collectively bonded by thermo-compression bonding to thechip electrode pads 8 a of the LSI chip 8 on which the bumps 7 have beenformed. Then, the encapsulating resin 9 is allowed to flow into thespace formed by the device-mounting film portion 91 b and the surface ofthe LSI chip 8, thereby fixing and mounting the LSI chip 8 with respectto the device-mounting film portion 91 b. Next, external-connection filmportions 91 c and 91 e are respectively bent 180° at the bendingportions 91 d and 91 f in such a manner as to be superposed on abase-resin surface 91B (second surface) of the device-mounting filmportion 91 b, and are secured to the surface of the encapsulating resin9 by means of the adhesives 10 a and 10 b. Finally, the solder balls 11are deposited on the external electrode pads 5.

[0108] Thus, in accordance with the ninth embodiment, since theexternal-connection film portions 91 c and 91 e are provided on bothsides of the device-mounting film portion 91 b, the length of the wiring(inner leads) from each chip electrode pad to each correspondingexternal electrode pad can be made shorter than in the above-describedfirst embodiment, so that more efficient routing of the wiring becomespossible. Hence, the operating speed of the LSI chip can be made faster.

[0109] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the LSI chip 8 is fixedly mounted inthe state in which the base-resin surface side of the device-mountingfilm portion faces the surface of the LSI chip 8. Furthermore, it ispossible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

[0110] A 10th embodiment of the present invention is characterized inthat after the external-connection film portions formed on both side ofthe package film are bent; the encapsulating resin is allowed to flowin, and the LSI chip is mounted on the package film. FIG. 10 is across-sectional structural view illustrating a semiconductor device inaccordance with the 10th embodiment of the present invention.Incidentally, in FIG. 10, those parts and portions which are identicalto those shown in FIGS. 1 to 9 are denoted by the same referencenumerals.

[0111] First, by using the package film 91 (see FIG. 9A) in accordancewith the above-described ninth embodiment, the inner-lead formingsurface 91A (first surface) of the package film 91 is set as the LSIchip 8 side. In the device-mounting film portion 91 b of the packagefilm 91, the inner leads 3 and the dummy inner leads 3 a arecollectively bonded by thermo-compression bonding to the chip electrodepads 8 a of the LSI chip 8 on which the bumps 7 have been formed. Then,the external-connection film portions 91 c and 91 e are respectivelybent 180° at the bending portions 91 d and 91 f in such a manner as tobe superposed on the base-resin surface 91 side.

[0112] Next, the encapsulating resin 9 is injected into a gap 91 gformed between the external-connection film portions 91 c and 91 e, withthe result that the LSI chip 8 is fixed and mounted on thedevice-mounting film portion 91 b, and the bent external-connection filmportions 91 c and 91 e are fixed to the device-mounting film portion 91b. Finally, the solder balls 11 are deposited on the external electrodepads 5.

[0113] Thus, in accordance with the 10th embodiment, since theexternal-connection film portions 91 c and 91 e are bent, and theencapsulating resin 9 is injected into the gap 91 g between theseexternal-connection film portions to fix and mount the LSI chip 8 andfix the external-connection film portion 91 c and 91 e, the adhesive forfixing the external-connection film portions as well as the step forfixing the external-connection film portions by the adhesive are madeunnecessary. Hence, it is possible to further lower the manufacturingcost.

[0114] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. Furthermore, it is possible to adopt the structure inwhich the solder balls 11 are not deposited on the external electrodepads 5.

[0115] An 11th embodiment of the present invention is characterized inthat the inner leads formed on the package film havingexternal-connection film portions on both sides of the device-mountingfilm portion are bonded directly on the electrode pads of the LSI chipwithout forming the bumps. FIG. 11 is a cross-sectional structural viewillustrating a semiconductor device in accordance with the 11thembodiment of the present invention. Incidentally, in FIG. 11, thoseparts and portions which are identical to those shown in FIGS. 1 to 10are denoted by the same reference numerals.

[0116] First, a package film 111 is fabricated. This package film 111 isarranged such that, in the package film 91 (see FIG. 9A) in accordancewith the above-described ninth embodiment, not the inner leads 3 but theinner leads 31 in which the copper foil used in the above-describedthird embodiment is provided with gold plating are formed by patterning.To lower the hardness of the inner leads 31, in the same way as in theabove-described third embodiment, annealing at 150° C. for 30 minutes orthereabouts is carried out. The inner leads 31 are collectively bondeddirectly to the chip electrode pads 8 a of the LSI chip 8 bythermo-compression bonding without the bumps. Incidentally, the othermanufacturing process is similar to that of the above-described ninthembodiment.

[0117] Thus, in accordance with the 11th embodiment, since the step forforming bumps on the electrode pads of the LSI chip becomes unnecessary,it is possible to reduce the manufacturing cost more than in theabove-described ninth embodiment, thereby making it possible to furtherlower the cost of the semiconductor device.

[0118] Incidentally, it goes without saying that this 11th embodiment isalso applicable to the above-described 10th embodiment. In addition, itis possible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

[0119] A 12th embodiment of the present invention is characterized inthat a protective frame for protecting the side surfaces and the reversesurface of the LSI chip is provided on the semiconductor device having astructure in which two external-connection film portions formed on bothside of the package film are bent. FIGS. 12A and 12B are cross-sectionalstructural views illustrating a semiconductor device in accordance withthe 12th embodiment of the present invention. Incidentally, in FIGS. 12Aand 12B, those parts and portions which are identical to those shown inFIGS. 1 to 11 are denoted by the same reference numerals.

[0120] The semiconductor device in accordance with the 12th embodimentis arranged such that the semiconductor device in accordance with theabove-described ninth embodiment is provided with the box-shapedprotective frame 41 shown in FIG. 12A or the bottomless protective frame42 shown in FIG. 12B. These protective frames 41 and 42 are the same asthose used in the above-described fourth embodiment, and are fixed tothe device-mounting film portion 91 b of the package film 91 by means ofan adhesive 10 c.

[0121] Thus, in accordance with the 12th embodiment, since thesemiconductor device having the structure in which the twoexternal-connection film portions are bent is provided with theprotective frame 41 or 42, the side surfaces and the reverse surface ofthe LSI chip 8 can be protected, with the result that it is possible toprevent the occurrence of the breakage of the side surfaces and thereverse surface of the LSI chip 8 during its handling, and animprovement in the yield during mounting can be expected.

[0122] Incidentally, it goes without saying that this 12th embodiment isalso applicable to the above-described 10th or 11th embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0123] A 13th embodiment of the present invention is characterized inthat a plate is provided for improving the flatness ofexternal-connection film portions which are formed on both sides of thepackage film and are respectively bent when the LSI chip is mounted onthe package film. FIG. 13 is a cross-sectional structural viewillustrating a semiconductor device in accordance with the 13thembodiment of the present invention. Incidentally, in FIG. 13, thoseparts and portions which are identical to those shown in FIGS. 1 to 12are denoted by the same reference numerals.

[0124] The semiconductor device shown in FIG. 13 is arranged such that,in the semiconductor device in accordance with the above-described ninthembodiment, the flat plate 51 formed of an insulating material or anelectrically conductive material such as a metal, which is used in theabove-described fifth embodiment, is provided between thedevice-mounting film portion 91 b of the package film 91 and theexternal-connection film portions 91 c and 91 e. This flat plate 51 isfixed between the surface of the encapsulating resin 9 of thedevice-mounting film portion 91 b and the external-connection filmportions 91 c and 91 e by using the adhesives 10 a, 10 b, and 10 c.

[0125] Thus, in accordance with the 13th embodiment, since the flatplate 51 is provided between the device-mounting film portion 91 b andthe external-connection film portions 91 c and 91 e, the flatness of theexternal-connection film portions 91 c and 91 e, i.e., the flatness ofthe solder balls 11, can be improved, thereby making it possible toimprove the mountability of the semiconductor device onto a motherboard. In addition, in the case where a metal plate or the like is usedas the flat plate, it is possible to improve the heat radiationcharacteristic of the semiconductor device.

[0126] Incidentally, it goes without saying that this 13th embodiment isalso applicable to the above-described 11th or 12th embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.Furthermore, a substantially U-shaped plate such as the one used in theabove-described sixth embodiment may be used instead of using the flatplate.

[0127] Further, by using an electrically conductive flat plate orsubstantially U-shaped plate, in the same way as in the above-describedseventh embodiment, the external-connection film portions may be formedas the two-layered structure in which both surfaces are electricallyconductive, wherein a reference power supply inner lead is formed on thepackage film 91, through holes are respectively provided in theexternal-connection film portions 91 c and 91 e, and the reference powersupply inner lead and the electrically conductive flat plate orsubstantially U-shaped plate are electrically connected via thesethrough holes. Consequently, since the crosstalk noise can be reduced,the operating speed of the LSI chip can be made even faster.

[0128] A 14th embodiment of the present invention is characterized inthat the external-connection film portions formed on both sides of thepackage film are respectively bent toward the reverse surface of the LSIchip and are fixed thereto. FIG. 14 is a diagram illustrating thestructure of a semiconductor device in accordance with the 14thembodiment of the present invention. Incidentally, in FIG. 14, thoseparts and portions which are identical to those shown in FIGS. 1 to 13are denoted by the same reference numerals.

[0129] First, as shown in FIG. 14, by using the package film 91 in theabove-described ninth embodiment (see FIG. 9A), the LSI chip 8 ismounted on the device-mounting film portion 91 b in a state in which thebase-resin surface 91B (second surface) of the device-mounting filmportion 91 b of the package film 91 faces the surface of the LSI chip 8.Namely, in the device-mounting film portion 91 b of the package film 91,the inner leads 3 are collectively bonded by thermo-compression bondingto the chip electrode pads 8 a of the LSI chip 8 on which the bumps 7have been formed. Then, the encapsulating resin 9 is allowed to flowinto the space formed by the device-mounting film portion 91 b and thesurface of the LSI chip 8, thereby fixing and mounting the LSI chip 8with respect to the device-mounting film portion 91 b.

[0130] Next, the external-connection film portions 91 c and 91 e arerespectively bent 180° at the bending portions 91 d and 91 f in such amanner as to be superposed on the reverse surface 8 b side of the LSIchip 8, and are secured to the reverse surface 8 b of the chip by meansof the adhesives 10 a and 10 b. Finally, the solder balls 11 aredeposited on the external electrode pads 5.

[0131] Thus, in accordance with the 14th embodiment, since theexternal-connection film portions 91 c and 91 e are bent toward thereverse surface 8 b of the LSI chip 8 and are secured thereto, it ispossible to protect the reverse surface 8 b and the side surfaces of theLSI chip 8 without using a protective frame or the like. In addition, itis possible to flatten the external-connection film portions 91 c and 91e without using a flat plate.

[0132] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdand 11th embodiments. Furthermore, it is possible to adopt the structurein which the solder balls 11 are not deposited on the external electrodepads 5.

[0133] A 15th embodiment of the present invention is characterized inthat the package film having external-connection film portions on foursides of the device-mounting film portion is used, and theseexternal-connection film portions are respectively bent. FIGS. 15A and15B are diagrams illustrating the structure of a semiconductor deviceand a manufacturing process in accordance with the 15th embodiment ofthe present invention. FIG. 15A is a front elevational view in which apackage film 151 used in this semiconductor device is viewed from ainner-lead forming surface 151A. FIG. 15B is a cross-sectionalstructural view, taken along line A-A′ of FIG. 15A, of the semiconductordevice in accordance with the 15th embodiment. Incidentally, in FIGS.15A and 15B, those parts and portions which are identical to those shownin FIGS. 1 to 14 are denoted by the same reference numerals.

[0134] First, the package film 151 shown in FIG. 15A is fabricated bythe same procedure as that of the above-described first embodiment.Namely, the inner leads 3 are formed by effecting patterning on the baseresin 2 in which the device hole 12 has been formed and a bending hole13 c has been formed in the shape of a frame in such a manner as tosurround the device hole 12. Then, the insulating resin 4 is formed byeffecting patterning thereon, thereby forming the external electrodepads 5. It should be noted that dummy inner leads are unnecessary. Inaddition, the elastic resin 6 should preferably be coated to prevent thedeterioration of the strength of the inner leads 3 in bending portions151 d, 151 f, 151 j, and 151 k (portions which respectively correspondto the four sides of the bending hole 13 c formed in the shape of asquare frame). The package film 151 is fabricated in the above-describedmanner.

[0135] Next, as shown in FIG. 15B, the LSI chip 8 is mounted on adevice-mounting film portion 151 b in a state in which the inner-leadforming surface 151A (first surface) of the device-mounting film portion151 b of the package film 151 faces the surface of the LSI chip 8.Namely, in the device-mounting film portion 151 b of the package film151, the inner leads 3 are collectively bonded by thermo-compressionbonding to the chip electrode pads 8 a of the LSI chip 8 on which thebumps 7 have been formed. Then, the encapsulating resin 9 is allowed toflow into the space formed by the device-mounting film portion 151 b andthe surface of the LSI chip 8, thereby fixing and mounting the LSI chip8 with respect to the device-mounting film portion 151 b. Next,external-connection film portions 151 c, 151 e, 151 h, and 151 i arerespectively bent 180° at the bending portions 151 d, 151 f, 151 j, and151 k in such a manner as to be superposed on a base-resin surface 151B(second surface) of the device-mounting film portion 151 b, and aresecured to the surface of the encapsulating resin 9 by means of theadhesives 10 a and 10 b. Finally, the solder balls 11 are deposited onthe external electrode pads 5.

[0136] Thus, in accordance with the 15th embodiment, since theexternal-connection film portions are respectively provided on the foursides of the device-mounting film portion 151 b, the length of thewiring (inner leads) from each chip electrode pad to each correspondingexternal electrode pad can be made shorter than in the above-describedninth embodiment, so that more efficient routing of the wiring becomespossible. Hence, the operating speed of the LSI chip can be made faster.

[0137] It should be noted that an arrangement may be provided such that,in the same way as in the above-described 10th embodiment, the fourexternal-connection film portions are bent, and the encapsulating resin9 is allowed to flow into the gap at the bent portions. Further, theinner leads may be bonded directly to the chip electrode pads 8 awithout using bumps as in the above-described third and 11thembodiments. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

[0138] A 16th embodiment of the present invention is characterized inthat the semiconductor device having the structure in which fourexternal-connection film portions are bent is provided with a protectiveframe for protecting the side surfaces and the reverse surface of theLSI chip or a flat plate for improving the flatness of the bentexternal-connection film portions. FIGS. 16A and 16B are cross-sectionalstructural views illustrating a semiconductor device in accordance withthe 16th embodiment of the present invention. Incidentally, in FIGS. 16Aand 16B, those parts and portions which are identical to those shown inFIGS. 1 to 15 are denoted by the same reference numerals.

[0139] The semiconductor device in accordance with the 16th embodimentis arranged such that the semiconductor device in accordance with theabove-described 15th embodiment is provided with the box-shapedprotective frame 41 shown in FIG. 16A or the bottomless protective frame42 shown in FIG. 16B. These protective frames 41 and 42 are the same asthose used in the above-described fourth embodiment, and are fixed tothe device-mounting film portion 151 b of the package film 151 by meansof an adhesive 10 c.

[0140] Thus, in accordance with the 16th embodiment, since thesemiconductor device having the structure in which the fourexternal-connection film portions are bent is provided with theprotective frame 41 or 42, the side surfaces and the reverse surface ofthe LSI chip 8 can be protected, with the result that it is possible toprevent the occurrence of the breakage of the side surfaces and thereverse surface of the LSI chip 8 during its handling, and animprovement in the yield during mounting can be expected.

[0141] It should be noted that, instead of using the protective film 41or 42, it is possible to adopt an arrangement in which a flat plate suchas the one used in the above-described fifth embodiment is providedbetween the four external-connection film portions and the surface ofthe encapsulating resin 9, or an arrangement in which both theprotective film 41 or 42 and the aforementioned flat plate are provided.Further, by using an electrically conductive flat plate, in the same wayas in the above-described seventh embodiment, the external-connectionfilm portions may be formed as the two-layered structure in which bothsurfaces are electrically conductive, wherein a reference power supplyinner lead is formed on the package film 151, through holes arerespectively provided in the four external-connection film portions, andthe reference power supply inner lead and the electrically conductiveflat plate are electrically connected via these through holes.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0142] A 17th embodiment of the present invention is characterized inthat the external-connection film portions formed on the four sides ofthe package film are respectively bent toward the reverse surface of theLSI chip and are fixed thereto. FIG. 17 is a diagram illustrating thestructure of a semiconductor device in accordance with the 17thembodiment of the present invention. Incidentally, in FIG. 17, thoseparts and portions which are identical to those shown in FIGS. 1 to 16are denoted by the same reference numerals.

[0143] First, as shown in FIG. 17, by using the package film 151 in theabove-described 15th embodiment (see FIG. 15A), the LSI chip 8 isfixedly mounted on the device-mounting film portion 151 b in the sameprocedure as that of the above-described 14th embodiment in the state inwhich the base-resin surface 151B (second surface) of thedevice-mounting film portion 151 b of the package film 151 faces thesurface of the LSI chip 8. Next, the four external-connection filmportions including the external-connection film portions 151 c and 151 eare respectively bent 180° at the four bending portions including thebending portions 151 d and 151 f in such a manner as to be superposed onthe reverse surface 8 b side of the LSI chip 8, and are secured to thereverse surface 8 b of the chip by means of the adhesives 10 a and 10 b.Finally, the solder balls 11 are deposited on the external electrodepads 5.

[0144] Thus, in accordance with the 17th embodiment, since the fourexternal-connection film portions are bent toward the reverse surface 8b of the LSI chip 8 and are secured thereto, it is possible to protectthe reverse surface 8 b and the side surfaces of the LSI chip 8 withoutusing a protective frame or the like. In addition, it is possible toflatten the external-connection film portions without using a flatplate.

[0145] Incidentally, the external electrode pads may be formed on thebase-resin surface side of the package film as in the above-describedsecond embodiment. In this case, the inner-lead forming surface of theexternal-connection film portion is bonded to the reverse surface of theLSI chip 8. Further, the inner leads may be bonded directly to the chipelectrode pads 8 a without using bumps as in the above-described thirdembodiment. Furthermore, it is possible to adopt the structure in whichthe solder balls 11 are not deposited on the external electrode pads 5.

[0146] An 18th embodiment of the present invention is characterized inthat an LSI chip in which the chip electrode pads are formed in thevicinity of a center line on the chip surface is used. FIGS. 18A to 18Care diagrams illustrating the structure of a semiconductor device and amanufacturing process in accordance with the 18th embodiment of thepresent invention. FIG. 18A is a plan view of an external connectionsurface 181A of a package film 181 used in this semiconductor device.FIG. 18B is a cross-sectional structural view taken along line A-A′ ofFIG. 18A. FIG. 18C is a cross-sectional structural diagram of thissemiconductor device. Incidentally, in FIGS. 18A to 18C, those parts andportions which are identical to those shown in FIGS. 1 to 17 are denotedby the same reference numerals.

[0147] As shown in FIGS. 18A and 18B, with respect to an LSI chip 182 inwhich chip electrode pads 182 a are formed in a region along a chipcenter line F, the package film 181 having a device hole 183 in a regionalong the center line F is fabricated in correspondence with the regionof the LSI 182 where the chip electrode pads are formed, in the sameprocedure as that of the above-described second embodiment. At thistime, the bending hole is not formed, and the size of the package film181 is set to be substantially identical as the size of the LSI chip.

[0148] Next, as shown in FIG. 18C, in the same procedure as that of theabove-described second embodiment, the inner leads 3 are bonded to thechip electrode pads 182 a of the LSI chip 182, the LSI chip 182 ismounted on the package film 181 (however, there is no step for bendingthe package film), and the solder balls 11 are deposited on the externalelectrode pads 22.

[0149] Thus, in accordance with the 18th embodiment, since the LSI chip182 in which the chip electrode pads 182 a are formed along the chipcenter line is mounted on the package film 181 having the device hole183 at the position corresponding to the chip-electrode-pad formingregion and having substantially the same size as the LSI chip 182, aspecial elastic adhesive and a substrate whose coefficient of thermalexpansion differs from that of the LSI chip are not used, it is possibleto improve the reliability of the semiconductor device. In addition, itis possible to reduce the number of processing steps (the number ofbending steps of the package film) and reduce the material cost, therebymaking it possible to further lower the cost of the semiconductordevice. Moreover, a more compact and lightweight semiconductor devicecan be realized as compared with the above-described first embodiment.

[0150] It should be noted that the inner leads may be bonded directly tothe chip electrode pads as in the above-described third embodiment.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 22.

[0151] A 19th embodiment of the present invention is characterized inthat an LSI chip in which the chip electrode pads are formed in acentral portion of the chip surface is used. FIGS. 19A and 19B arediagrams illustrating the structure of a semiconductor device and amanufacturing process in accordance with the 19th embodiment of thepresent invention. FIG. 19A is a plan view of an external connectionsurface 191A of a package film 191 used in this semiconductor device.FIG. 19B is a cross-sectional structural view, taken along line A-A′ ofFIG. 19A, of the semiconductor device in accordance with the 19thembodiment. Incidentally, in FIGS. 19A and 19B, those parts and portionswhich are identical to those shown in FIGS. 1 to 18 are denoted by thesame reference numerals.

[0152] First, as shown in FIG. 19A, with respect to an LSI chip 192 inwhich chip electrode pads 192 a are formed in a vicinity of a centralportion of the chip, the package film 191 having a device hole 193 inits central portion is fabricated in correspondence with the region ofthe LSI 192 where the chip electrode pads are formed, in the sameprocedure as that of the above-described first embodiment. The size ofthe package film 191 is set to be substantially identical as the size ofthe LSI chip 192. In addition, the position and shape of the device hole193 are set to correspond to those of the chip-electrode-pad formingregion of the LSI chip 192. In the package film 191, the externalelectrode pads 5 are formed on the inner-lead forming surface side, andthe inner-lead forming surface is used as the external connectionsurface 191A. Meanwhile, the resin surface of the package film 191 isused as a device mounting surface 191B which is the side where the LSIchip 191 is mounted.

[0153] Next, as shown in FIG. 19C, in the same procedure as that of theabove-described first embodiment, the inner leads 3 are collectivelybonded to the chip electrode pads 192 a of the LSI chip 192, the LSIchip 192 is mounted on the device mounting surface 191B side of thepackage film 191 (however, there is no step for bending the packagefilm), and the solder balls 11 are deposited on the external electrodepads 5.

[0154] Thus, in accordance with the 19th embodiment, since the LSI chip192 in which the chip electrode pads 192 a are formed on the centralportion of the chip is mounted on the package film 191 having the devicehole 193 at a position corresponding to the chip-electrode-pad formingregion and having substantially the same size as that of the LSI chip192, a special elastic adhesive and a substrate whose coefficient ofthermal expansion differs from that of the LSI chip are not used, and itis possible to improve the reliability of the semiconductor device. Inaddition, it is possible to reduce the number of processing steps (thenumber of bending steps of the package film) and reduce the materialcost, thereby making it possible to further lower the cost of thesemiconductor device. Moreover, a more compact and lightweightsemiconductor device can be realized as compared with theabove-described first embodiment.

[0155] It should be noted that the inner leads may be bonded directly tothe chip electrode pads as in the above-described third embodiment.Furthermore, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0156] A 20th embodiment of the present invention is characterized inthat a package film having insulating resin projections on the devicemounting surface is used in the above-described 18th or 19th embodiment.FIG. 20 is a cross-sectional view illustrating the structure of asemiconductor device in accordance with the 20th embodiment of thepresent invention. Incidentally, in FIG. 20, those parts and portionswhich are identical to those shown in FIGS. 1 to 19 are denoted by thesame reference numerals.

[0157] The semiconductor device shown in FIG. 20 is arranged such thatnot the package film 181 but a package film 201 having insulating resinprojections on the device mounting surface is used in the semiconductordevice in accordance with the 18th embodiment. Insulating resinprojections 202 are provided on a device mounting surface 201B of thepackage film 201. These insulating resin projections 202 can be easilyformed by coating the base resin 2 with the inner leads 3 patternedthereon with an insulating resin, and by subjecting this insulatingresin to photolithographic etching.

[0158] Next, in the same procedure as that of the above-described 18thembodiment, the inner leads 3 are bonded to the chip electrode pads 182a of the LSI chip 182, and the encapsulating resin 9 is allowed to flowinto the space between the surface of the LSI chip 182 and the packagefilm 201, thereby fixing and mounting the LSI chip 182. At this time,the encapsulating resin 9 is allowed to flow in by arranging the packagefilm 201 and the LSI chip 182 such that top portions 202 a of theinsulating resin projections 202 abut against the surface of the LSIchip 182. In addition, the insulating resin projections 202 have thefunction of making the encapsulating resin 9 to flow and of improvingthe flatness of the package film 201.

[0159] Thus, in accordance with the 20th embodiment, since theinsulating resin projections 202 are provided on the device mountingsurface 201B of the package film 201, the flow of the encapsulatingresin 9 is facilitated, and it is possible to improve the flatness ofthe package film 201, thereby making it possible to improve the qualityof the package.

[0160] Incidentally, it goes without saying that this 20th embodiment isalso applicable to the above-described 19th embodiment. In addition, itis possible to adopt the structure in which the solder balls 11 are notdeposited on the external electrode pads 5.

[0161] A 21st embodiment of the present invention is characterized inthat the semiconductor device using a package film having a device holeformed in a region along its central portion or its center line isprovided with a protective frame for protecting the side surfaces andthe reverse surface of the LSI chip. FIGS. 21A and 21B arecross-sectional structural views illustrating a semiconductor device inaccordance with the 21st embodiment of the present invention.Incidentally, in FIGS. 21A and 21B, those parts and portions which areidentical to those shown in FIGS. 1 to 20 are denoted by the samereference numerals.

[0162] The semiconductor device in accordance with the 21st embodimentis arranged such that the semiconductor device in accordance with theabove-described 19th embodiment is provided with a box-shaped protectiveframe 211 shown in FIG. 21A or a bottomless protective frame 212 shownin FIG. 21B. These protective frames 211 and 212 are fixed to the devicemounting surface 191B of the package film 191 by using the adhesive 10.

[0163] Thus, in accordance with the 21st embodiment, since theprotective frame 211 or 212 is provided, the side surfaces and thereverse surface of the LSI chip 192 can be protected, with the resultthat it is possible to prevent the occurrence of the breakage of theside surfaces and the reverse surface of the LSI chip 192 during itshandling, and an improvement in the yield during mounting can beexpected.

[0164] Incidentally, it goes without saying that this 21st embodiment isalso applicable to the above-described 18th or 20th embodiment. Inaddition, it is possible to adopt the structure in which the solderballs 11 are not deposited on the external electrode pads 5.

[0165]FIG. 22 is a cross-sectional structural diagram illustrating asemiconductor device in accordance a 22nd embodiment of the presentinvention. Incidentally, in FIG. 22, those parts and portions which areidentical to those shown in FIGS. 1 to 21 are denoted by the samereference numerals.

[0166] The semiconductor device shown in FIG. 22 is comprised of apackage film 221 and the LSI chip 192 used in the above-described 19thembodiment. The package film 221 is arranged such that fourexternal-connection film portions including external-connection filmportions 221 c and 221 h are provided on the four sides of adevice-mounting film portion 221 b via four bending portions includingbending portions 221 d and 221 i as in the case of the package film 151(see FIG. 15A) in accordance with the above-described 15th embodiment.

[0167] First, the package film 221 is fabricated. Namely, in the sameprocedure as that of the above-described first embodiment, the innerleads 3 are formed by effecting patterning on the base resin 2 in whichthe device hole 193 has been formed in its central portion incorrespondence with the chip-electrode-pad forming region of the LSIchip 192 and a bending hole has been formed in the shape of a frame insuch a manner as to surround the device hole 193. Then, the insulatingresin 4 is formed by effecting patterning thereon, thereby forming theexternal electrode pads 5. The external electrode pads 5 are formed alsoon the inner-lead forming surface (first surface) of the device-mountingfilm portion 221 b. The device-mounting film portion 221 b has the samestructure as that of the package film 191 in accordance with theabove-described 19th embodiment (see FIG. 19A), and the package film 221has the structure in which four external-connection film portions areprovided in the package film 191 in accordance with the above-described19th embodiment (however, the device hole 193 in the device-mountingfilm portion 221 b is illustrated as the device hole 193 in the packagefilm 191 which has been rotated 45°). Incidentally, the elastic resin 6should preferably be coated to prevent the deterioration of the strengthof the inner leads 3 in the four bending portions. The package film 221is fabricated in the above-described manner.

[0168] Next, in the same way as in the above-described 19th embodiment,the LSI chip 192 is mounted on the device-mounting film portion 221 b ina state in which the base resin surface (second surface) of thedevice-mounting film portion 221 b faces the surface of the LSI chip192. Namely, the inner leads 3 are collectively bonded bythermo-compression bonding to the chip electrode pads 192 a of the LSIchip 192 on which the bumps 7 have been formed. Then, the encapsulatingresin 9 is allowed to flow into the space formed by the device-mountingfilm portion 221 b and the surface of the LSI chip 192, thereby fixingand mounting the LSI chip 192 on the device-mounting film portion 221 b.

[0169] Next, the four external-connection film portions (theexternal-connection film portions 221 c, 221 h, etc.) are respectivelybent 180° at the four bending portions (bending portions 221 d, 221 j,etc.) in such a manner as to be superposed on a reverse surface 192 b ofthe LSI chip 192, and are secured to the reverse surface 192 b of thechip by means of the adhesives 10 a, 10 b, and the like. Finally, thesolder balls 11 are respectively deposited on the external electrodepads 5 on the four external-connection film portions. Here, the solderballs 11 are not deposited on the external electrode pads 5 of thedevice-mounting film portion 221 b.

[0170] As for the semiconductor device shown in FIG. 22, a plurality ofsemiconductor devices can be laminated. The number of the semiconductordevices to be laminated is assumed to be N (N is an integer equal to orgreater than 2). The external-connection film portions of a firstsemiconductor device and the device-mounting film portion 221 b of asecond semiconductor device are made to face each other, and the twosemiconductor devices are laminated in such a manner that the respectiveexternal electrode pads 5 are superposed on each other. Then, the solderballs 11 deposited on the external electrode pads 5 of the firstsemiconductor device are melted to electrically connect the superposedexternal electrodes. As a result, the second semiconductor device islaminated and fixed on the first semiconductor device. Similarly, thirdto Nth semiconductor devices are laminated. The melting of the solderballs 11 may be effected collectively after the N semiconductor deviceshave been superposed one on top of another. However, in the case wherethe external-connection film portions of the first semiconductor deviceand the device-mounting film portion 221 b of the second semiconductordevice are made to face each other in the above-described manner, it isnecessary to form the external electrode pads 5 of theexternal-connection film portions in such a manner as to correspond tothe positions where the external electrode pads 5 of the device-mountingfilm portion 221 b are formed. Incidentally, the semiconductor devicesmay be laminated in a state in which the device-mounting film portions221 b or the external-connection film portions of the respectivesemiconductor devices are made to face each other. It goes withoutsaying that a plurality of the semiconductor devices shown in FIG. 22can be laminated and mounted on a mother board in the same procedure asthe one described above.

[0171] Thus, in accordance with the 22nd embodiment, since the externalelectrode pads 5 are also provided on the device-mounting film portion221 b, and the external-connection film portions are fixed to thereverse surface of the LSI chip, it is possible to reduce the wiringlength, protect the reverse surface of the LSI chip, and flatten theexternal-connection film portions, and the laminated mounting on themother board (three-dimensional mounting) becomes possible. Hence, itbecomes possible to reduce the mounting space in the mother board.Further, it is possible to lower the cost of the semiconductor devicesand improve the reliability.

[0172] It should be noted that two external-connection film portions maybe provided on both sides of the device-mounting film portion 221 b asin the case of the above-described ninth embodiment. In addition, thesolder balls 11 may be deposited only on the device-mounting filmportion. Further, the solder balls 11 may or may not be deposited onboth the external-connection film portions and the device-mounting filmportion. Moreover, the inner leads may be bonded directly to the chipelectrode pads as in the case of the above-described third embodiment.Additionally, insulating resin projections such as those of theabove-described 20th embodiment may be provided on a second surface ofthe device-mounting film portion 221 b.

[0173]FIG. 23 shows a cross-sectional structural diagram illustrating asemiconductor device in accordance with a 23rd embodiment of the presentinvention. Incidentally, in FIG. 23, those parts and portions which areidentical to those shown in FIGS. 1 to 22 are denoted by the samereference numerals.

[0174] The semiconductor device shown in FIG. 23 is comprised of apackage film 231 and an LSI chip 232 in which chip electrode pads 232 aare formed in a peripheral portion of the chip surface. The package film231 is comprised of a device-mounting film portion 231 b, anexternal-connection film portion 231 c, and a bending portion 231 dlocated therebetween.

[0175] First, the package film 231 is fabricated. Namely, in the sameprocedure as that of the above-described first embodiment, the innerleads 3 are formed by effecting patterning on the base resin 2 in whicha device hole 233 has been formed in its peripheral portion incorrespondence with the chip-electrode-pad forming region of the LSIchip 232 and a bending hole has been formed. Then, the insulating resin4 is formed by effecting patterning thereon, thereby forming theexternal electrode pads 5. The external electrode pads 5 are formed alsoon the inner-lead forming surface of the device-mounting film portion231 b. Although the device hole 233 is not a hole as such, but a notchedportion provided in the peripheral portion. However, since its functionis identical to that of the device hole 183 in accordance with theabove-described 18th embodiment, it is referred to as the “hole.”Incidentally, the elastic resin 6 should preferably be coated to preventthe deterioration of the strength of the inner leads 3 in the bendingportion. The package film 231 is fabricated in the above-describedmanner.

[0176] Next, in the same way as in the above-described 19th embodiment,the LSI chip 232 is mounted on the device-mounting film portion 231 b ina state in which the base resin surface of the device-mounting filmportion 231 b faces the surface of the LSI chip 232. Namely, the innerleads 3 are collectively bonded by thermo-compression bonding to thechip electrode pads 232 a of the LSI chip 232 on which the bumps 7 havebeen formed. Then, the encapsulating resin 9 is allowed to flow into thespace formed by the device-mounting film portion 231 b and the surfaceof the LSI chip 232, thereby fixing and mounting the LSI chip 232 on thedevice-mounting film portion 231 b.

[0177] Next, the external-connection film portion 231 c is bent 180° atthe bending portion 231 d in such a manner as to be superposed on areverse surface 232 b of the LSI chip 232, and is secured to the reversesurface 232 b of the chip by means of the adhesive 10. Finally, thesolder balls 11 are deposited on the external electrode pads 5 on theexternal-connection film portion 231 c. Here, the solder balls 11 arenot deposited on the external electrode pads 5 of the device-mountingfilm portion 231 b.

[0178] As for the semiconductor device shown in FIG. 23, a plurality ofsemiconductor devices can also be laminated in the same way as in theabove-described 22nd embodiment. Accordingly, a plurality of thesemiconductor devices shown in FIG. 22 can be laminated and mounted on amother board.

[0179] Thus, in accordance with the 23rd embodiment, since the externalelectrode pads 5 are also provided on the device-mounting film portion231 b, and the external-connection film portion 231 c is fixed to thereverse surface of the LSI chip, it is possible to reduce the wiringlength, protect the reverse surface of the LSI chip, and flatten theexternal-connection film portion, and the laminated mounting on themother board (three-dimensional mounting) becomes possible. Hence, itbecomes possible to reduce the mounting space in the mother board.Further, since one external-connection film portion is used, it ispossible to improve the positional accuracy of the external electrodepads 5 as compared with the above-described 22nd embodiment.

[0180] It should be noted that the solder balls 11 may be deposited onlyon the device-mounting film portion 231 d. Further, the solder balls 11may or may not be deposited on both the external-connection film portion231 c and the device-mounting film portion 231 b. Moreover, the innerleads may be bonded directly to the chip electrode pads as in the caseof the above-described third embodiment. In addition, a plurality ofexternal-connection film portions may be provided. Further, insulatingresin projections such as those of the above-described 20th embodimentmay be provided on the second surface of the device-mounting filmportion 231 b. Still further, it is possible to adopt a structure inwhich the external-connection film portion and the bending portion arenot provided as in the case of the above-described 18th or 19thembodiment.

[0181] It should be noted that the mounting of the semiconductor deviceon the mother board is effected as described below. Referring to FIGS.27A and 27B, a description will be given by citing as an example thesemiconductor device in accordance with the first embodiment.

[0182]FIG. 27A shows a schematic cross-sectional view of a mother board300 on which the semiconductor device in accordance with the firstembodiment is mounted. First, prior to the mounting of the semiconductordevice, the solder balls 11 are deposited on electrode pads 302 of themother board 300. Next, the semiconductor device is placed on the motherboard 300. At that time, the semiconductor device is placed in such away that the electrode pads 302 of the mother board 300 correspond tothe external electrode pads 5 of the semiconductor device. Finally, thesolder balls 11 are melted to electrically connect the mother board 300and the semiconductor device.

[0183] Since the solder balls 11 are deposited on the mother board 300,it becomes possible to mount a plurality of packages simultaneously.Hence, there is an advantage in that the number of steps of mounting thesemiconductor devices on the mother board 300 can be reduced. Inaddition, since the step for depositing the solder balls 11 on theexternal electrode pads 302 becomes unnecessary in the process formanufacturing the semiconductor device, there is an advantage in thatthe number of processing steps can be reduced, and it is possible tofurther lower the cost of the packages.

[0184] Further, in the 22nd and 23rd embodiments, in the case where aplurality of semiconductor devices are laminated and mounted on themother board 300, the procedure described below is taken. Referring toFIG. 28, a description will be given by citing the semiconductor deviceof the 23rd embodiment as an example.

[0185]FIG. 28 shows a state in which two semiconductor devices areplaced on the mother board 300 in a superposed manner, and areelectrically connected. To laminate such a plurality of semiconductordevices, first, the external electrode pads formed on either theexternal-connection film portion or the device-mounting film portion ofthe first semiconductor device are superposed on the electrode pads 302of the mother board 300, and the external electrode pads formed oneither the external-connection film portion or the device-mounting filmportion of the second semiconductor device are superposed on theexternal electrode pads formed on another film portion of the firstsemiconductor device, such that the superposed electrodes areelectrically connected. It should be noted that the electricalconnection is established as the solder balls 11 are deposited inadvance on the mother board 300 and the semiconductor devices betweenthe superposed electrodes, and the solder balls 11 are then melted.

[0186] In accordance with the above-described method, an advantage canbe obtained in that since a plurality of semiconductor devices arelaminated and mounted, the mounting space on the mother board can besaved.

What is claimed is:
 1. A semiconductor device comprising a package filmincluding: a device-mounting film portion on which a semiconductor chipis mounted; an external-connection film portion arranged on saiddevice-mounting film portion and having an external electrode pad formedthereon; a bending portion provided between an end portion of saiddevice-mounting film portion and an end portion of saidexternal-connection film portion; and an inner lead for electricallyconnecting an electrode pad of said semiconductor chip and said externalelectrode pad via said bending portion.
 2. A semiconductor deviceaccording to claim 1, further comprising: a flat plate provided betweensaid device-mounting film portion and said external-connection filmportion.
 3. A semiconductor device according to claim 2, wherein saidexternal-connection film portion has a through hole, said flat plate iselectrically conductive, an inner lead for a reference power supplyleading from an electrode pad for the reference power supply of saidsemiconductor chip is formed on said package film via said bendingportion, and an electrically conductive material is embedded in thethrough hole to electrically connect said inner lead for the referencepower supply and said electrically conductive flat plate.
 4. Asemiconductor device according to claim 1, further comprising: asubstantially U-shaped plate including a bottom plate portion and a topplate portion, wherein said device-mounting film portion is attached toan inner surface of said bottom plate portion of said substantiallyU-shaped plate, and said external-connection film portion is attached toan outer surface of said top plate portion.
 5. A semiconductor devicecomprising a package film including: a device-mounting film portion onwhich a semiconductor chip is mounted such that said device-mountingfilm portion faces an obverse surface of said semiconductor chip; anexternal-connection film portion arranged on a reverse surface of saidsemiconductor chip and having an external electrode pad formed thereon;a bending portion provided between an end portion of saiddevice-mounting film portion and an end portion of saidexternal-connection film portion; and an inner lead for electricallyconnecting an electrode pad of said semiconductor chip and said externalelectrode pad via said bending portion.
 6. A semiconductor devicecomprising a package film on which a semiconductor chip having anelectrode pad arranged in a region along a central portion of said chipor a center line of said chip is mounted, wherein said package filmincludes: a device hole formed in a region along a central portionthereof or a center line thereof in correspondence with the region wheresaid electrode pad of said semiconductor chip is formed; an externalelectrode pad formed in a region other than the region where the devicehole is formed; and an inner lead connecting said electrode pad of saidsemiconductor chip and said external electrode pad.
 7. A semiconductordevice comprising a package film on which a semiconductor chip having anelectrode pad arranged in a peripheral portion of said chip is mounted,wherein said package film includes: a device hole formed in a peripheralportion thereof in correspondence with the region where said electrodepad of said semiconductor chip is formed; an external electrode padformed in a region other than the region where the device hole isformed; and an inner lead connecting said electrode pad of saidsemiconductor chip and said external electrode pad, wherein a spacebetween said package film and a surface of said semiconductor chip isfixed by an encapsulating resin.
 8. A semiconductor device according toclaim 1, 6, or 7, wherein a protective frame is provided in such amanner as to cover side surfaces or side surfaces and a reverse surfaceof said semiconductor chip.
 9. A semiconductor device comprising apackage film including: a device-mounting film portion on which asemiconductor chip having an electrode pad arranged in a predeterminedregion is mounted such that said device-mounting film portion faces anobverse surface of said semiconductor chip; an external-connection filmportion arranged on a reverse surface of said semiconductor chip andhaving an external electrode pad formed thereon; a bending portionprovided between an end portion of said device-mounting film portion andan end portion of said external-connection film portion; and an innerlead, wherein said device-mounting film portion has a device hole formedin a predetermined region in correspondence with a region where anelectrode pad of said semiconductor chip is formed and an externalelectrode pad formed in a region other than the region where the devicehole is formed, and said inner lead electrically connects said electrodepad of said semiconductor chip and said external electrode pad of saiddevice-mounting film portion, and electrically connects said electrodepad of said semiconductor chip and said external-connection film portionvia said bending portion.
 10. A semiconductor device according to claim9, wherein said external-connection film portion has said externalelectrode pad formed at a position corresponding to anexternal-electrode-pad forming position on said device-mounting filmportion.
 11. A semiconductor device wherein a plurality of semiconductordevices according to claim 10 are laminated, said semiconductor devicesbeing superposed such that said external electrode pad of some filmportion of a first semiconductor device is superposed on said externalelectrode pad of some film portion of a second semiconductor device suchthat said superposed external electrode pads are electrically connectedto each other.
 12. A semiconductor device according to claim 10, whereina solder ball is deposited on one of said external electrode pad formedon said external-connection film portion and said external electrode padformed on said device-mounting film portion.
 13. A semiconductor deviceaccording to claim 6, 7, or 9, wherein said package film has insulatingresin projections formed on its surface where said semiconductor chip ismounted.
 14. A semiconductor device according to claim 1, 5, or 9,wherein said package film has a plurality of bending portions, and has aplurality of said external-connection film portions, in such a manner asto respectively correspond to said plurality of bending portions.
 15. Asemiconductor device according to claim 14, wherein said package filmhas two bending portions and two external-connection film portions, insuch a manner as to respectively correspond to two opposing sides ofsaid semiconductor chip.
 16. A semiconductor device according to claim14, wherein said package film has four bending portions and fourexternal-connection film portions, in such a manner as to respectivelycorrespond to four sides of said semiconductor chip.
 17. A semiconductordevice according to claim 1, 5, 6, 7, or 9, wherein said bending portionhas a structure in which said inner lead is coated with an elasticresin.
 18. A semiconductor device according to claim 1, 5, 6, 7, or 9,wherein said inner lead is bonded directly to said electrode pad of saidsemiconductor chip.
 19. A semiconductor device according to claim 18,wherein said inner lead is formed by subjecting a gold-plated copperfoil to annealing.
 20. A semiconductor device according to claim 1, 5,6, 7, or 9, wherein a solder ball is deposited on said externalelectrode pad.
 21. A method for manufacturing a semiconductor device,comprising the steps of: preparing a package film having a planarconfiguration whose region is divided into a device-mounting filmportion having a device hole forming therein, an external-connectionfilm portion, and a bent portion located between said device-mountingfilm portion and said external-connection film portion, an externalelectrode pad being formed on said external-connection film portion on afirst surface side of said package film, an inner lead being formed insuch a manner as to lead from the device hole to said external electrodepad via said bending portion; mounting a semiconductor chip on saiddevice-mounting film portion on said first surface side by bonding saidinner lead to an electrode pad of said semiconductor chip in a regionwhere the device hole is formed; and bending said external-connectionfilm portion at said bending portion 180° toward a second surface sideof said package film and fixing the same.
 22. A method for manufacturinga semiconductor device according to claim 21, wherein the step ofmounting said semiconductor chip is effected such that after said innerlead is bonded to said electrode pad of said semiconductor chip, anencapsulating resin is allowed to flow into a space between saiddevice-mounting film portion and an obverse surface of saidsemiconductor chip so as to fix said semiconductor chip on saiddevice-mounting film portion.
 23. A method for manufacturing asemiconductor device according to claim 21, wherein said package filmhas a plurality of bending portions and has a plurality of saidexternal-connection film portions, in such a manner as to respectivelycorrespond to said plurality of bending portions, and the step of fixingsaid external-connection film portion is effected by respectivelybending said plurality of external-connection film portions atcorresponding said bending portions 180° toward said second surface sideand by fixing the same.
 24. A method for manufacturing a semiconductordevice according to claim 23, wherein the step of fixing saidexternal-connection film portion is effected by allowing anencapsulating resin to flow from a gap at each of said plurality ofexternal-connection film portions bent into a space between each of saidexternal-connection film portions and said device-mounting film portionand a space between said device-mounting film portion and the obversesurface of said semiconductor chip, for fixing said semiconductor chipon said device-mounting film portion and fixing said external-connectionfilm portions to said device-mounting film portion.
 25. A method formanufacturing a semiconductor device according to claim 23, wherein saidpackage film has two bending portions and two external-connection filmportions, in such a manner as to respectively correspond to two opposingsides of said semiconductor chip, and the step of fixing saidexternal-connection film portion is effected by respectively bendingsaid two external-connection film portions at corresponding said bendingportions 180° toward said second surface side and by fixing the same.26. A method for manufacturing a semiconductor device according to claim23, wherein said package film has four bending portions and fourexternal-connection film portions, in such a manner as to respectivelycorrespond to four sides of said semiconductor chip, and the step offixing said external-connection film portion is effected by respectivelybending said four external-connection film portions at correspondingsaid bending portions 180° toward said second surface side and by fixingthe same.
 27. A method for manufacturing a semiconductor device,comprising the steps of: preparing a package film having a planarconfiguration whose region is divided into a device-mounting filmportion having a device hole forming therein, an external-connectionfilm portion, and a bent portion located between said device-mountingfilm portion and said external-connection film portion, an externalelectrode pad being formed on said external-connection film portion on afirst surface side of said package film, an inner lead being formed insuch a manner as to lead from the device hole to said external electrodepad via said bending portion; mounting a semiconductor chip on saiddevice-mounting film portion on a second surface side of said packagefilm by bonding said inner lead to an electrode pad on an obversesurface of said semiconductor chip in a region where the device hole isformed; and bending said external-connection film portion at saidbending portion 180° toward a reverse surface side of said semiconductorchip and fixing the same to said reverse surface.
 28. A method formanufacturing a semiconductor device, comprising the steps of: preparinga semiconductor chip having an electrode pad arranged in a region alonga central portion of said chip or a center line of said chip, as well asa package film having a device hole formed in a region along a centralportion thereof or a center line thereof in correspondence with theregion where said electrode pad of said semiconductor chip is formed, anexternal electrode pad being formed on an external connection surfaceside of said package film in a region other than the region where thedevice hole is formed, an inner lead being formed in such a manner as tolead from the device hole to said external electrode; and mounting saidsemiconductor chip on a device mounting surface side of said packagefilm by bonding said inner lead to said electrode pad of saidsemiconductor chip in the region where the device hole is formed.
 29. Amethod for manufacturing a semiconductor device, comprising the stepsof: preparing a semiconductor chip having an electrode pad arranged in aperipheral portion of said chip, as well as a package film having adevice hole formed in a peripheral portion thereof in correspondencewith the region where said electrode pad of said semiconductor chip isformed, an external electrode pad being formed on an external connectionsurface side of said package film in a region other than the regionwhere the device hole is formed, an inner lead being formed in such amanner as to lead from the device hole to said external electrode; andmounting said semiconductor chip on a device mounting surface side ofsaid package film by bonding said inner lead to said electrode pad ofsaid semiconductor chip in the region where the device hole is formed,and by allowing an encapsulating resin to flow into a space between saidpackage film and an obverse surface of said semiconductor chip.
 30. Amethod for manufacturing a semiconductor device according to claim 28 or29, wherein said package film has insulating resin projections formed onits surface where said semiconductor chip is mounted, and the step ofmounting said semiconductor chip is effected such that after said innerlead is bonded, an encapsulating resin is allowed to flow into a spacebetween said package film and said semiconductor chip so as to fix saidsemiconductor chip on said package film.
 31. A method for manufacturinga semiconductor device, comprising the steps of: preparing asemiconductor chip having electrode pads arranged in a predeterminedregion thereof, as well as a package film having a planar configurationwhose region is divided into a device-mounting film portion having adevice hole forming in a determined region thereof, anexternal-connection film portion, and a bent portion located betweensaid device-mounting film portion and said external-connection filmportion, external electrode pads being formed on saidexternal-connection film portion on a first surface side of said packagefilm and in a region other than the region where the device hole isformed in said device-mounting film portion on said first surface side,inner leads being formed in such a manner as to lead from the devicehole to respective said external electrode pads; mounting saidsemiconductor chip on said device-mounting film portion on a secondsurface side of said package film by bonding said inner leads to saidelectrode pads on an obverse surface of said semiconductor chip in aregion where the device hole is formed; and bending saidexternal-connection film portion at said bending portion 180° toward areverse surface side of said semiconductor chip and fixing the same tosaid reverse surface.
 32. A method for manufacturing a semiconductordevice according to claim 31, wherein said device-mounting film portionhas insulating resin projections formed on said second surface side, andthe step of mounting said semiconductor chip is effected such that aftersaid inner leads are bonded, an encapsulating resin is allowed to flowinto a space between said device-mounting film portion and saidsemiconductor chip so as to fix said semiconductor chip on said secondsurface of said device-mounting film portion.
 33. A method formanufacturing a semiconductor device according to claim 31, wherein saidexternal-connection film portion has said external electrode pads formedat positions corresponding to an external-electrode-pad forming positionon said device-mounting film portion, said method of manufacturing asemiconductor device further comprising the steps of: preparing aplurality of semiconductor devices for each of which the step of fixingsaid external-connection film portion has been completed; and laminatingsaid plurality of semiconductor devices by superposing said externalelectrode pads of some film portion of a first semiconductor device onsaid external electrode pads of some film portion of a secondsemiconductor device such that said superposed external electrode padsbeing electrically connected to each other.
 34. A method formanufacturing a semiconductor device according to claim 33, wherein, inthe step of laminating said plurality of semiconductor devices, solderballs are selectively deposited on said external electrode pads of saidsemiconductor devices for which the step of fixing saidexternal-connection film portion has been completed such that selectedones of said superposed external electrode pads have said solder balls,and said solder balls are melted, thereby electrically connecting saidsuperposed external electrode pads.
 35. A method for manufacturing asemiconductor device according to claim 27 or 31, wherein said packagefilm has a plurality of bending portions and has a plurality of saidexternal-connection film portions, in such a manner as to respectivelycorrespond to said plurality of bending portions, and the step of fixingsaid external-connection film portion is effected by respectivelybending said plurality of external-connection film portions atcorresponding said bending portions 180° toward said reverse surfaceside of said semiconductor chip and by fixing the same to said reversesurface.
 36. A method for manufacturing a semiconductor device accordingto claim 35, wherein said package film has two bending portions and twoexternal-connection film portions, in such a manner as to respectivelycorrespond to two opposing sides of said semiconductor chip, and thestep of fixing said external-connection film portion is effected byrespectively bending said two external-connection film portions atcorresponding said bending portions 180° toward said reverse surfaceside of said semiconductor chip and by fixing the same to said reversesurface.
 37. A method for manufacturing a semiconductor device accordingto claim 35, wherein said package film has four bending portions andfour external-connection film portions, in such a manner as torespectively correspond to four sides of said semiconductor chip, andthe step of fixing said external-connection film portion is effected byrespectively bending said four external-connection film portions atcorresponding said bending portions 180° toward said second surface sideand by fixing the same.
 38. A method for manufacturing a semiconductordevice according to claim 21, 27, or 31, further comprising the stepsof: preparing a base resin which has a planar configuration and whoseregion is divided into a predetermined region for a device-mounting filmportion, a predetermined region for a bending portion, and apredetermined region for a external-connection film portion; andfabricating said package film by forming said device hole in saidpredetermined region for said device-mounting film portion of said baseresin, by forming said bending hole in said predetermined region forsaid bending portion, by patterning on said base resin said inner leadleading from said device hole to said predetermined region for saidexternal-connection film portion via said bending hole, and by formingsaid external electrode pad in said predetermined region for saidexternal-connection film portion.
 39. A method for manufacturing asemiconductor device according to claim 38, wherein, in the step offabricating said package film, said external electrode pad is formed bycoating said base resin with said inner lead patterned thereon with aninsulating resin, and by forming holes in said insulating resin.
 40. Amethod for manufacturing a semiconductor device according to claim 38,wherein, in the step of fabricating said package film, said externalelectrode pad is formed by patterning said inner lead leading to a holefor said external electrode pad on said base resin in which a hole forsaid external electrode pad has been formed.
 41. A method formanufacturing a semiconductor device according to claim 21, 27, 28, 29or 31, wherein, in the step of mounting said semiconductor chip, saidinner leads are collectively bonded to said electrode pads of saidsemiconductor chip.
 42. A method for manufacturing a semiconductordevice according to claim 21, 27, 28, 29 or 31, wherein, in the step ofmounting said semiconductor chip, said inner leads are bonded directlyto said electrode pads of said semiconductor chip.
 43. A method formounting a semiconductor device according to any one of claims 1 to 19on a mother board in close contact therewith, comprising the steps of:depositing solder balls on electrode pads of said mother board; andplacing said semiconductor device on said mother board and melting saidsolder balls so as to electrically connect said electrode pads of saidmother board and said external electrode pads of said semiconductordevice.
 44. A method for mounting a semiconductor device in which aplurality of superposed semiconductor devices according to claim 9 aremounted on a mother board, comprising the step of: causing said externalelectrode pads formed on one of said external-connection film portionand said device-mounting film portion of a first semiconductor device tobe superposed on said electrode pads of said mother board, and causingsaid external electrode pads formed on one of said external-connectionfilm portion and said device-mounting film portion of a secondsemiconductor device to be superposed on said external electrode padsformed on another film portion of said first semiconductor device, so asto electrically connect said superposed electrodes.
 45. A method formounting a semiconductor device according to claim 44, wherein saidsolder balls are deposited in advance between said superposedelectrodes, and said solder balls are melted, so as to electricallyconnect said superposed electrodes.